cryptobiosis

Cryptobiosis is a reversible state in which an animal's metabolism has come to a virtual standstill. Cryptobiosis is exhibited by various types
of organism, including the tardigrade (shown here). A tardigrade, or "water
bear," can go into a hibernation mode,
known as the tun state, that is more akin to suspended
animation whereby it can survive temperatures from -253°C to 151°C,
as well as exposure to X-rays, and vacuum
conditions. When tardigrades are placed in perfluorocarbon fluid (again
while hibernating), at a pressure of 600 MPa – almost 6,000 times
atmospheric pressure at sea level – they emerge from the experience
unharmed. See also cryobiology.